I recently purchased a Sony RX1R camera and an Epson 3880 printer to get back into serious amateur photography. In researching the printer, a major concern was in the cost to print images that I would offer to local art galleries to sell on consignment.
From a marketer's perspective, allowing the gallery maximum markup was critical, and cutting my costs to print so that I could make them competitive with a profit for me. Red River Paper's website was the absolute best site for detailed data as to the cost to print with the Epson 3880. Their charts were extremely helpful in making my decision.
Of course, then it was just courtesy to buy some paper from them, at least to give it a try. Having had a high quality Epson printer in the past in which I used only Epson paper, I can tell you that you don't lose a thing in buying from Red River Paper. Quality is excellent, and help in settings and production is available on their site. They're just great.